Resonant circuits are useful for various applications, such as filters and oscillators. The frequency of resonance can be adjusted in tunable resonant circuits to track application requirements and/or to compensate for variations in the manufacturing process, operating temperature, and operating voltage.
It has generally been recognized that there is a need to increase the range of tuning of resonant circuits. However, parasitic circuit elements generally limit the turning range of resonant circuits. One or more embodiments of the present invention may address one or more of the above issues.